1. Field of the Invention
The present invention relates to an autonomous moving apparatus and, in particular, to an autonomous moving apparatus that detects contacts with obstacles or the like while moving.
2. Description of the Related Art
An autonomous traveling vehicle that travels autonomously while detecting obstacles or the like has been researched and developed, and such a vehicle has been put into practical use as a transfer robot in warehouses and factories, for example. Such an autonomous traveling vehicle is disclosed in conventional arts as follows.
A conventional autonomous traveling vehicle can detect contacts with obstacles, or the like, with respect to all directions of a vehicle body. The autonomous traveling vehicle includes a rectangular vehicle body base plate and a box-shaped external cover arranged to cover the base plate. The vehicle body base plate and the external cover are connected with each other by a plurality of external cover connecting members. Eight micro switches provided to detect displacement of the external cover are arranged between a side portion of the vehicle body base plate and an inner surface of the external cover. When contacted by an obstacle, or the like, and resultantly acted on by external forces, the external cover moves horizontally, and the micro switch that is arranged in the vicinity of a contacted portion from among the eight micro switches is turned on. Thus, the contact of the autonomous traveling vehicle with the obstacle can be detected.
A conventional obstacle detecting device of an unmanned transfer vehicle including a movable bumper surrounding an unmanned transfer vehicle main body and a sensor arranged to detect the movement of the bumper has the following configuration. The bumper of the unmanned transfer vehicle includes a main body frame arranged on a side surface of the unmanned transfer vehicle main body; elastic supporting members arranged at four corners of the main body frame; and a bumper frame that is suspended by or mounted on the elastic supporting members. The sensor of the obstacle detecting device includes a contact sensor arranged on an external side of the bumper frame; a proximity sensor arranged on an inner side of the bumper frame; and a proximity sensor arranged on an upper surface of the main body frame.
A conventional autonomous robot has the following configuration. The autonomous robot includes a main body that can travel by being driven and an exterior portion that extends along an entire circumference of the main body and is attached to the main body via a force sensor, thereby detecting collisions of the exterior portion with obstacles or the like based on outputs from the force sensor.
In the above conventional autonomous traveling vehicle, the eight micro switches are provided around an entire circumference of a side surface of the vehicle body in order to detect the contacts or collisions with respect to all directions (i.e., front, back, right, and left directions). As a result, the configuration of the autonomous traveling vehicle becomes complicated and costly, and the productivity and reliability of the autonomous traveling vehicle is decreased. Therefore, a technique that can detect the contacts or collisions with respect to all directions by fewer detection devices during the autonomous movement has been desired.
A similar problem can be found in the configuration of the above obstacle detecting device. That is, contacts with obstacles or the like cannot be detected by a tape switch (i.e., by the contact sensor) unless a detection surface of the tape switch makes contact with such obstacles. Therefore, the tape switch detects such contacts only when an obstacle or the like makes contact with a width portion of the tape, thereby resulting in local detections. Further, if a great number of tape switches are provided in order to evenly detect the contacts with respect to all directions, a manufacturing cost is increased. Furthermore, the proximity sensor of the obstacle detecting device can detect only the contacts in a horizontal direction, and accordingly, when the bumper moves obliquely in an upper direction, for example, the contacts with the obstacles may not be detected.
On the other hand, in the configuration of the autonomous robot, the collisions with the obstacles can be determined by detecting, through the force sensor, the moment generated on the exterior portion when the exterior portion collides with the obstacles. However, when compared with a binary sensor, which is turned on and off, the force sensor may be expensive, leaving room for improvement in view of manufacturing cost reduction.